Field of the Invention
The present invention relates to an apparatus for examining or inspecting bottles for finding out defects such as flaw, contamination or the like, if any, through applying a light from a light source and receiving the light reflected by the bottles irregularly due to the presence of the defects.
Conventionally, there has been proposed and used photoelectric bottle inspecting apparatus having lighting means adapted to apply light to bottles to be inspected, and a group of light receiving elements, so as to detect the defects in the bottle, if any, through irregularity of reflected light.
This conventional technique, however, has suffered from disadvantage of difficulty in optimumly positioning the light receiving elements in relation with the random direction of irregularly reflected light, as well as difficulty in receiving all part of reflected light, which hinders the apparatus of this kind from being put into practical use.
According to another conventional technique, the defects are detected by photoelectric light receiving element or elements responsive to the reduction of quantity of light passing through the bottle due to the presence of defects.
This technique is also unsatisfactory especially for such effect as would not produce a sufficiently large contrast of the light having passed through the defective part to that having passed through the sound part of the bottle, e.g. kink, shell-shaped flaw, voids and so on, although it may be effectively used in detecting such defects as would hardly pass the light, e.g. inclusion of stones or other foreign matters and contamination.